Fix two production billing bugs: invoice missing oven cost, quote stuck in Draft after send

Bug 1 — Invoice total didn't match job total for direct jobs:
- Root cause: all three item-save paths in JobsController passed null for
  ovenCostId, so FinalPrice/ShopSuppliesAmount were stored without oven cost
  while the Details page recalculated live with OvenCostId and showed higher.
- Add OvenBatchCost stored field to Job entity (migration AddJobOvenBatchCost,
  default 0 for existing rows).
- Fix Create, Edit, and UpdateItems to pass job.OvenCostId and save OvenBatchCost.
- Fix InvoicesController.Create GET for direct jobs to use stored OvenBatchCost
  and ShopSuppliesAmount as separate labeled lines instead of recalculating
  shop supplies from scratch (which excluded the oven cost base).

Bug 2 — Quote status stayed Draft after "Send Quote via Email":
- ResendQuote advanced the approval token and sent the email but never
  updated the status. Added Draft → Sent advancement (same guard used by
  the SMS send path) so the status updates on successful email send.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Controllers/InvoicesController.cs

@@ -458,21 +458,36 @@ public class InvoicesController : Controller
                     dto.TaxPercent = sourceQuote.TaxPercent;
                     dto.DiscountAmount = sourceQuote.DiscountAmount;
                 }
-                else if (hadJobItems && costs?.ShopSuppliesRate > 0)
+                else if (hadJobItems)
                 {
-                    // Direct job — no source quote. Derive shop supplies from the items subtotal
-                    // using the current company rate. (Quote-sourced jobs read the pre-agreed amount
-                    // from the quote snapshot instead; this path only fires when there is no quote.)
-                    var itemsSubtotal = dto.InvoiceItems.Sum(i => i.TotalPrice);
-                    var shopSuppliesAmount = Math.Round(itemsSubtotal * (costs.ShopSuppliesRate / 100m), 2);
-                    if (shopSuppliesAmount > 0.01m)
+                    // Direct job — no source quote. Use the stored job-level fees rather than
+                    // recalculating, so the invoice always matches the total shown on the job page.
+                    // OvenBatchCost and ShopSuppliesAmount are saved by the pricing engine (with
+                    // OvenCostId) when job items are created or updated.
+                    if (job.OvenBatchCost > 0.01m)
                     {
                         dto.InvoiceItems.Add(new CreateInvoiceItemDto
                         {
-                            Description = $"Shop Supplies ({costs.ShopSuppliesRate:0.##}%)",
+                            Description = $"Oven Processing Fee",
                             Quantity = 1,
-                            UnitPrice = shopSuppliesAmount,
-                            TotalPrice = shopSuppliesAmount,
+                            UnitPrice = Math.Round(job.OvenBatchCost, 2),
+                            TotalPrice = Math.Round(job.OvenBatchCost, 2),
+                            DisplayOrder = order++,
+                            RevenueAccountId = defaultRevenueAccount?.Id
+                        });
+                    }
+
+                    if (job.ShopSuppliesAmount > 0.01m)
+                    {
+                        var suppliesDesc = job.ShopSuppliesPercent > 0
+                            ? $"Shop Supplies ({job.ShopSuppliesPercent:0.##}%)"
+                            : "Shop Supplies";
+                        dto.InvoiceItems.Add(new CreateInvoiceItemDto
+                        {
+                            Description = suppliesDesc,
+                            Quantity = 1,
+                            UnitPrice = Math.Round(job.ShopSuppliesAmount, 2),
+                            TotalPrice = Math.Round(job.ShopSuppliesAmount, 2),
                             DisplayOrder = order,
                             RevenueAccountId = defaultRevenueAccount?.Id
                         });